Question

I’ve got a problem with following code. A class id is Long, B class id is an embedded id where one of its fields is A class.

DetachedCriteria dc = DetachedCriteria.forClass(A.class,"a").setProjection(Property.forName("a.id"));      
Criteria cr= this.sessionFactory.getCurrentSession().createCriteria(B.class,"b").add(Subqueries.in("b.id.a.id", dc));           
List<B> bb = cr.list();

This gives exception:

java.lang.ClassCastException: java.lang.String cannot be cast to java.lang.Long

But this:

List<Long> dd =  this.sessionFactory.getCurrentSession().createCriteria(A.class,"a").setProjection(Property.forName("a.id")).list();
Criteria cr= this.sessionFactory.getCurrentSession().createCriteria(B.class,"b").add(Restrictions.in("b.id.a.id", dd));


List<B> bb = cr.list();

works. What am I doing wrong?

Answer 1

It appeared that “Subqueries.propertyIn” should be used in this situation.